In recent years, there has been remarkable advancement of electronic communication techniques in a mobile terminal device typified by a portable telephone. Such a mobile terminal device has become multifunctional and of higher functionality caused by convenience, and the range of application of the mobile terminal device is now expanding. Examples of multifunctionality and higher functionality include, e.g., a communication function such as Internet, an electronic mail function, a game, playback of music, reception of FM broadcasts, and the like.
Incidentally, as a result of a progress in digitization of satellite broadcasts and terrestrial broadcasts, high image quality, interactive (interacting) broadcasts involving audience participation, and digital broadcasts which enable data broadcasts have become possible. In addition to digitization of the broadcasts by audio and images, data broadcasts such as a weather forecast, stock market information, and various news have become digitized and aired.
A portable telephone having a built-in TV tuner has also been known, as described in, e.g., Patent Document 1. In the fields of terrestrial digital broadcasts and satellite digital broadcasts, broadcasts using a one-segment or three-segment transmission band designed mainly for a compact receiver having high portability are scheduled.
Under the above-described circumstances, a device capable of receiving, replaying, and recording the above digital broadcasts are desirably integrated into a single device, with a portable telephone typified by a mobile terminal device.
However, constraints such as life and power capacity of a battery and recording capacity cannot be surmounted by mere integration of an existing portable telephone and the above digital broadcast receiving apparatus.
One example configuration of a digital broadcast receiving apparatus intended for a case where a portable telephone and a device capable of receiving digital broadcasts are integrated by an existing method is described by reference to FIG. 13.
An antenna 713, a transmitting/receiving section 714, a nonvolatile memory 715, a camera 716, an operation section 717, and a microphone (MIC) 711 are provided for fulfilling the basic functions of the portable telephone.
The configuration of the digital broadcast receiving apparatus illustrated in FIG. 13 will now be described.
A broadcast wave is received by an antenna 701 for receiving a broadcast wave, and a channel is selected by a tuner section 702 used for tuning a frequency to a designated program. The signal extracted by the tuner section 702 is demodulated by a demodulation section 703, and the demodulation section 703 outputs a transport stream (TS).
Here, TS is information in which an image signal (a video signal), a voice signal (an audio signal) and a data signal have been multiplexed. Specific examples of TS will be described in association with descriptions of embodiments of the present invention by reference to FIG. 2.
When the transport stream (TS) output from the demodulation section 703 is scrambled, a descrambler 704 descrambles the scrambled TS.
A TS separating section 705 separates the descrambled transport stream (TS) into a video signal, an audio signal and a data signal.
The video signal separated by the TS separating section 705 is decoded by a video signal decoding section 707, and the decoded signal is displayed as an image on a display section 709. The audio signal separated by the TS separating section 705 is demodulated by an audio signal decoding section 706, and the demodulated signal is output as sound from a speaker 710.
The data signal separated by the TS separating section 705 is processed by a data signal processing section 708, to thus be converted into display data, whereupon the data are displayed in the form of characters, numerals, or drawings on the display section 709.
A control section 712 controls the portable telephone or tuning operation of the tuner section 702.
When digital broadcasts are recorded by the above digital broadcast receiving apparatus, a designated program is recorded at a designated time by a method for re-encoding the video signal and the audio signal, which have been replayed as mentioned previously, or by recording a transport stream.
Patent Document 1: JP-A-2002-9920